Valve cut-off mechanism



No Model.)

J. DOW.

VALVE GUT-OFF MECHANISM.

No. 310,189. Patented Jan. 6, 1885.

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UNITED STATES PATENT OFFICE.

JOSIAH DOlV, OF LOVELL, MASSACHUSETTS.

VALVE CUT-OFF MECHANISM.

SPECIFICATION forming part of Letters Patent No. 310,189, dated January 6, 1885.

Application filed July 19, 1884. (No model.)

T 0 CL whom it may concern Be it known that I, J osrnn Dow, a citizen of the United States, residing at Lowell, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Valve Gut-Off Mechanisms; and I do hereby declare that the same are fully described in the following specification, and illustrated in the accompanying drawings.

This invention relates to valve cut-off mechanism for opening and closing rotary valves on duplex crank-piston engines, although it may be equally well adapted to operate rotary valves on engines of other construction, or on pumps or similar machines.

The present invention relates to improvements on the application for a patent filed by me March 10, 1884, and allowed June 17, 1884; and it consists in a certain construction and arrangement of parts, by which the device is much simplified, and by which the valves are operated much easier and with less frictional resistance, without any jars and with greater accuracy of motion as compared with my previous invention. It is carried out as follows, reference being had to the accompanying drawings, where Figure 1 represents a central longitudinal section, and F1 2 represents a cross-section on the line AB shown in Fig. 1. Fig. 3 represents a cross-section of the movable ring for actuating the valve-disks to close the rotary valves.

Similar letters refer to similar parts wherever they occur on the different parts of the drawings.

a is the drivingrshaft, to which is secured the rotary cylinder b and its annular flange or bearingpiece 0 for the valve-stems d d, in the same manner as shown and described in my previous invention aforesaid.

(1 represents one of the rotary valves at tached to or made in one piece with its stem (1.

c is the stationary head of the ,engine with its outwardly-extending steam-chest e, which latter is provided with an inwardly centrallyproject-ing bearing-sleeve, 6, provided with a stuffinggland, c", as shown and described in my previous invention above mentioned.

To the exterior of bearing-sleeve c is secured the stationary ring f, and on said bearing-sleeve eis also arranged the movable ring g, the latter being toothed and operated by means of worm h on the worm-shaft h, which latter is geared or otherwise connected to a suitable governor, (not shown in the drawings) by means of which it is turned in either direction around the sleeve 0, to regulate the amount of cut-ofl, as may be desired. Each valve-stem d has secured to its outer end a single disk, 2', provided on its outer face with valve-closing pins or projections itt", and 011 its inner face with valve-opening pins or projections 1;" i t, as shown in Figs. 1 and 2. An annular groove, f, is made on the ring f to permit the disks z i to turn around freely when the shaft a and its cylinder 1) are rotated. Such groovef may be made in ring 9, or in any other suitable manner, as may be desired, without departing from the spirit of my invention.

I I are the hubs of the disks i 1 and in prac tice I prefer to provide each valve stem d with a metal or composition bearing-sleeve,c,where the stem (1 passes through the outer portion of the flanged bearing-piece c, and I provide the sleeve 0 with an outer flange, 0, located between the end of hub I and outer portion of flanged bearing-piece 0,- but I do not wish to confine myself to this exact construction, as it maybe done by other means.

The ring f, which is stationary, and which I term the valveopening ring, has at one place on its outer periphery a projection, F, in the side of which is a cam-groove, F, formed in part in projection F and partly in the periphey of the ring f, where a slight depression, F, is made, as shown in the dotted lines in Fig. 2. The movable ring g-,which I term the valve-closing ring, has also at one place on its periphery a projection, G, with a side cam-groove, G, and peripheral depression G, as shown in Figs. 2 and 3. The pins 73 t t" on one side of the disks i are located alternately with the pins *6 i '6 on the opposite side of such disks tthat is, the pins on one side are located midway between the pins 011 the opposite side of the disks, as shown in Fig. 2.

The operation of the device is as follows: As the shaft a, cylinder 1), and bearing'piece a rotate and carry with them the valve-stems d d and disks 1 'i, the latter are automatically turned one-sixth of a revolution around their fnlcra, first by one of their inner pins, 2', entering the groove F and depression F, and passes out through the rear end of such groove F, allowing such disk thus acted on withits respective valve (7/, to remain in an open position and to be held so during half a revolution, more or less, of the shaft (0 by two successive pins, 4." and t, lying in contact with the outer surfaces of the respective rings 9 andf. After the axle or shaft a has made about half a revolution, more or less, the nearest pin t" on the rear of the disk '1', the valve of which is open, is acted on by the groove G in the project-ion G, and its depres sion G and the disk i is thereby turned around its axis with its valve (1 another one-sixth of a revolution, causing its valve to be closed and to remain so until another half of a revolution, more or less, of the shaft to has been made, and so on. The duration of time in which the valve (1 remains open depends upon the relative positions of the respectiveringsf 1/ and their opening and closing grooves F G.

It will be seen that in my present invention I employ only one disk i for each valve-stem, and provide such disk with alternate opening and closing pinson opposite sides of each such disk. I also simplify said disks by having them of a true cylindrical shape without any external canrsnrfaces for holding them in open and closed positions, as shown in my previous invention. By the present device the disks are operated with a minimum of frictional re sistance and without any jar or noise,by which they are made to last much longer, thus dispensing with costly and unnecessary repairs.

Having thus fully described the nature, construction, and operation of my invention, 1' wish to secure by Letters Patent and claim 1.' The single disk 17, attached to the valvestem cl of the valve and provided with opposite and alternate opening and closing pins i i, in combination with the opening and el.os ing ringsf and ,having the respective projections F G and cam-grooves F F G G, as and for the purpose set forth.

2. In a valve-operating mechanism, the retary cylinder I), shaft (1, and flanged bearing piece or bracket 0, carrying the valve-stem d,

and its single disk t, having the opposite al- U ternate pins t" 6 upon it, in combination with the stationary ring f and its opening device F F F; and the movable ring 5 and its closing device G G G, as and for the purpose set forth.

3. In combination with the bearing-bracket 0, its stem (2, and disk vi, the bearingsleeve 0, having flange 0 located between the outside of bracket or bearing-piece c and huh I of the disk '1', as and for the purpose set forth.

at. In a valve-operating mechanism, the sin gle disk i with its side projections, '13, in combination with the stationary ring f, having cam-groove F F, for automatically turning the disk 2' for the purpose of opening its valve (1, as set forth and described.

.3. In a valve-operating mechanism, the sinl, gle disk '1' with its side projections, 73, in combination with the adjustable ring having cam-groove G G, for automatically closing the valve (1 on which the disk is attached, as and for the purpose set forth.

In testimony whereof I have afiixcd m y signaturein presence of two witnesses.

JOSIAH DO \V. \Vitncsscs:

.ToHN F. CURTIS, Cnlxs. II. Gmnnicx. 

